A rate-dependent elastoplastic ordinary state-based peridynamic model for concrete under impact loading

The complex deformation and fracture behaviors of concrete under impact loading, including tension–compression asymmetry, nonlinear equation of state, plasticity sensitivity, nonlocal effects, and discontinuous fracture, pose significant challenges to constitutive modeling and fracture simulation. Ordinary state-based peridynamics (OSB-PD) shows promise for addressing these challenges, with advantages in nonlocality, elimination of zero-energy modes, and dynamic fracture modeling. However, its advancement is hindered by two critical issues: the lack of a clear elastoplastic constitutive framework analogous to classical continuum mechanics, and the absence of OSB-PD models that simultaneously capture all these complex behaviors. This paper proposes such a framework, defining OSB-PD invariants, constitutive relations, and yield criteria with correspondences to classical counterparts. Based on this framework, a rate-dependent elastoplastic OSB-PD model for concrete is developed, incorporating key mechanical features under impact loading. The simulations results of the model are consistent with the experimental data from the three-point bending beam and SHPB tests, capturing the nail-like crack tip in bending tests and the double-peak phenomenon in SHPB tests. The proposed framework extends readily to other elastoplastic models and demonstrates significant potential for concurrent handling of material fracture and deformation under dynamic loading.